用java编程语言实现

设计一个表示圆柱体的类Cylinder，它继承自类Circle，还包含有表示圆柱体高的protected类型的成员变量h、获取和设置h值的public方法、计算圆柱体体积的public方法，用java实现

public class Cylinder extends Circle {
    protected double h;
    public Cylinder(double r, double h) {
        super(r);
        this.h = h;
    }

    public double getHeight() {
        return h;
    }

    public void setHeight(double h) {
        this.h = h;
    }

    public double getVolume() {
        return super.getArea() * h;
    }
}

public class Circle {
    protected double r; 
    public Circle(double r) {
        this.r = r;
    }

    public double getRadius() {
        return r;
    }

    public void setRadius(double r) {
        this.r = r;
    }

    public double getArea() {
        return Math.PI * r * r;
    }
}

public class Test {
    public static void main(String[] args) {
        Cylinder cylinder = new Cylinder(2.0, 3.0);
        System.out.println("圆柱体体积：" + cylinder.getVolume());
    }
}